The reliability of skeletal age determination in an Iranian sample using Greulich and Pyle method

Since introduction of Greulich and Pyle (GP) method for bone age determination, several studies have been performed for evaluation of applicability of this method in different geographic and ethnic groups. In this study we investigated the accuracy of this method in Iranian population.

425 (303 male and 122 female) healthy children aged between 6 and 18 years old, without genetic, metabolic, endocrine, growth or nutritional disorders who had plain hand and wrist radiographs were enrolled. All radiographs were taken for an indication of trauma from January 2009 to August 2010. Both sexes were divided into three subgroups (6-10, 10-14, 14-18 years old). Skeletal age (SA) was determined according to GP atlas by a radiologist who was blind to chronological age (CA). Mean CA was compared with mean SA in whole population, each sex group and in each age subgroup. Difference score (DS) was calculated by subtracting SA from CA and determined for whole population, each sex group and also for each age subgroup. Statistical analysis was performed using t-test and ANNOVA correlation test.

Considering whole study population, mean SA was 12.15±4.16 years and mean CA was 12.4±4.09 years and mean difference score (CA-SA) was 0.25±0.95 years. In male subjects mean SA was 12.68±4.07 years and mean CA was 13.04±3.93 years and mean difference score was 0.37±0.98 years (equal to 4.5 months). In female subjects mean SA was 10.84±4.11 and mean CA was 10.81±4.06 and mean difference score of girls was -0.04±0.78 years (equal to -0.5 month). DS shows no significant difference among three age subgroups in either male (P(value)=0.63) and female (P(value)=0.59) group.

According to this study skeletal age of boys was 4.5 months less than chronological age, but in girls skeletal age was 0.5 month more than it. Considering the possibility of few months difference, GP atlas could be applicable in Iranian children with acceptable accuracy.